Original URL: https://www.theregister.com/2002/08/28/popular_ms_download_has_mysterious/

Popular MS download has mysterious vuln

Remote root, but don't worry

By Thomas C Greene

Posted in Security, 28th August 2002 17:27 GMT

A certain remote root vulnerability in a Microsoft application called File Transfer Manager (FTM), a gimmick for developers, beta testers and volume license addicts (i.e., most of their corporate customers) alike, is not serious and there's almost no chance that some wily blackhat has used it against you.

Honestly, you're safe because "Microsoft believes that only a small number of customers actually are at risk."

Redmond's FTM is used by beta testers, MSDN members, clients of the Microsoft Volume Licensing Service, and participants in "a small number of other Microsoft programs" to download software from "certain Microsoft sites."

"The FTM is only distributed through these programs, but not every member has installed it. Even among customers who have installed it, not all are at risk, as only certain versions contain the vulnerability," the company says.

It's the classic MS security-bulletin formula: "The vulnerability is 'important' (never 'dangerous'); you have nothing to fear and no reason to regret trusting us; we have no intention of apologizing for it or even explaining it adequately; now go get your patch, shut up, and be grateful nothing bad has happened."

Only this alert went out via e-mail, exclusively to people registered in one of those few MS programs [and I thank the fifteen or twenty of you who promptly forwarded it to me], rather than being broadcast widely to catch the 'certain number' of users whose originally registered e-mail no longer works.

Finally, MS thanks Ukrainian researcher Andrew Tereschenko "for identifying the security vulnerability and working with us as we developed a solution."

Some truth

Actually, Tereschenko has something to add: several interesting details MS decided you'd be better off not knowing.

First, we learn that the FTM ActiveX control is susceptible to a buffer overflow while parsing input strings passed via a script to the 'Persist' function. "One of confirmed scenarios is a long (>12Kb) string used as 'TS=' (TransferSession?) value." he writes.

"Since the control is signed by Microsoft and marked as safe for scripting it's possible for any Web site to install it (with little warning, or without warning if a user trusts MSFT)."

He says the distribution is "medium-high, not a 'small number of customers,'" as MS claims.

Secondly, the FTM ActiveX control can download or upload files to or from any local directory via a schedule list without any user interaction. This can be done by setting "TGT=" and "TGN=" params during call to "Persist" function, he says.

FTM versions prior to 4.0, which MS urges on users as a fix, are susceptible to a man-in-the-middle attack. The attack is currently unconfirmed because MS has since updated its servers, but there's no reason to believe it wasn't used before then, and there's no guarantee it still cant be used if victims haven't updated their own FTM version.

Tereschenko recommends that all users search for TransferMgr.exe inside "%SYSTEMROOT%\Downloaded Program Files" and follow the instructions MS has laid out if the file is found. ®